The AllPrep DNA/RNA Mini Kit allows the simultaneous purification of genomic DNA and total RNA from the same biological sample. DNA is purified using the novel AllPrep DNA spin column. RNA is purified from the AllPrep column flow-through using an RNeasy Mini spin column. The kit can be automated on the QIAcube, and is compatible with up to 107 cells or 30 mg tissue.

Genomic DNA and total RNA were purified from 10-fold serial dilutions of rat kidney homogenate using the AllPrep DNA/RNA Micro Kit; at each dilution, DNA was purified from duplicates, and RNA was purified from 4 replicates. [A] Real-time PCR analysis of the Pgk1 gene and [B] real-time RT-PCR analysis of the Jun transcript showed reliable quantification over a wide dynamic range, from 5 mg down to 50 ng tissue.

The AllPrep DNA/RNA Mini Kit is designed for purifying both genomic DNA and total RNA from a single cell or tissue sample. Since there is no need to divide the sample into two for separate purification procedures, maximum yields of DNA and RNA can be achieved. The purified DNA and RNA are eluted separately and ready to use in any downstream application.

Procedure

A simple workflow allows the purification of high-quality DNA and RNA from the same sample in as little as 35 minutes (see flowchart "AllPrep DNA/RNA procedure"). Both cultured cells and easy-to-lyse tissues can be processed. Genomic DNA is purified using the novel AllPrep DNA spin column, and total RNA is purified using an RNeasy Mini spin column. A supplementary protocol allows optional purification of protein. For experiments where DNA, RNA, and protein are regularly prepared from each sample, the AllPrep DNA/RNA/Protein Mini Kit can be used instead.

When disrupting and homogenizing tissues in Buffer RLT Plus (supplied with the AllPrep DNA/RNA Mini Kit), excessive foaming may occur. This foaming is substantially reduced by adding Reagent DX (supplied separately) to Buffer RLT Plus at a final concentration of 0.5% (v/v) before starting disruption and homogenization. Reagent DX has been carefully tested with the kit, and has no effect on RNA purity or on downstream applications such as real-time RT-PCR. Buffer RLT Plus containing Reagent DX can be stored at room temperature (15–25ºC) for at least 9 months.

Applications

The purified genomic DNA with an average length of 15–30 kb, depending on homogenization conditions, is suited for any application, including Southern-, dot-, and slot-blot analyses; and PCR and multiplex PCR.

The purified total RNA can be used in any application, such as: RT-PCR and real-time RT-PCR; differential display; cDNA synthesis; northern-, dot-, and slot-blot analyses; and microarrays.

A supplementary protocol allows optional purification of protein. The purified protein is denatured and can be used in applications such as SDS-PAGE, western blotting, and 2D gel electrophoresis.